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5 Written questions

- a complex carrier mechanism located on the inside of the inner mitochondrial membrane
- two parts: electron transfer and ATP generation + the proton pump

- most efficient catabolic pathway to harvest energy stored in glucose
- occurs in mitochondrion and catalyzed by reaction specific enzymes
- produces 36-38 ATP
- aerobic, O₂ acts as the final acceptor of electrons that are passed from carrier to carrier during the final stage of glucose oxidation
- three stages: pyruvate decarboxylation, citric acid cycle and electron transport chain

- stored in adipose tissue in the form of triglyceride
- when needed, they are hydrolyzed by lipases to fatty acids and glycerol, and are carried by the blood to other tissues for oxidation
- glycerol can be converted into PGAL
- a fatty acid must be "activated" first in the cytoplasm, this requires 2 ATP
- on active, it is transorted into mitochondrion and taken through a series of "beta-oxidation cycles" that convert it into two carbon fragments, then converted to acetyl CoA, which enter TCA cycle.
- each round of beta oxidation generates 1 NADH and 1 FADH₂
-fats yield the most ATP per gram

- obtain energy catabolically
- break down organic nutrients that must be ingested

- ATP is produced when high energy potential electrons are transferred from NADH and FADH₂ to oxygen by a series of carrier molecules located in the inner mitochondrial membrane
- as the electrons are transferred from carrier to carrier, free energy is released
- later this energy is used to form ATP

5 Matching questions

AMP

Energy Carriers

Glycolysis

The Citric Acid Cyle (TCA Cycle)

Lactic Acid Fermentation

a- occurs in certain fungi and bacteria and in human muscle cells during strenuous activity
- happens when oxygen supply to muscle cells lags behind the rate of glucose catabolism
- pyruvate generated is reduced to lactic acid, which can lower blood pH if accumulated, eventually becomes muscle fatigue
- oxygen debt: the amount of oxygen needed to oxidize lactic acid back to pyruvate and enters cellular respiration

b- known as the Krebs cycle or the tricarboxylic acid cycle (TCA cycle)
- begins when the two carbon acetyl group from acetyl CoA combines with oxaloacetate, a four carbon molecule, to form the six carbon citrate
- 2CO₂ are released, oxaloacetate is regenerated to use for another turn of the cycle
- 1 cycle = 1 ATP produced by substrate level phosporylation via GTP intermediate
- electrons are transferred to NAD⁺ and FAD, generating NADH and FADH₂, which transport electrons to electron transport chain

c- molecular carriers used by the cell to shuttle energy between reactions
- ATP, NAD⁺, FAD

e- series of reactions that lead to the oxidative breakdown of glucose into two molecules of pyruvate, the production of ATP and reduction of NAD⁺ into NADH
- occurs in cytoplasm
- mediated by specific enzymes

5 Multiple choice questions

- NAD⁺, FAD, NADP⁺
- transport the high energy electrons of the hydrogen atoms to a series of carrier moelcules on the inner mitochondrial membrane (electron transport chain)

Carrier Coenzymes

Cytochromes

Carbohydrates

Energy Carriers

- occurs in yeast and bacteria only
- pyruvate produced in glycolysis is decarboxylated to acetaldehyde, then reduced by NADH in step 5 of glycolysis to yield ethanol
- pyruvate --> acetaldehyde --> ethanol

Cellular Respiration

Alcohol Fermentation

Fermentation

Lactic Acid Fermentation

- without oxygen, ETC becomes backlogged with electrons and NAD⁺ can't be regenerated to continue glycolysis without lactic acid fermentation occuring
- Cyanide and dinitrophenol works the same way.
- Cyanide blocks the transfer of electrons from Cytochrome a₃ to O₂
- Dinitrophenol uncouples the electron transport chain from the proton gradient established across the inner mitochondrial membrane

Cytochromes

Cytochrome a₃

ETC without )₂

Heterotrophic

- loss of an electron
- NAD⁺, FAD, NADP⁺ are referred to as oxidizing agents because they cause other molecules to lose electrons and undergo oxidation (while they're reduced NADH, FADH₂, NADPH)

Oxidation

Fats

Reduction

ATP

- disaccharides are hydrolyzed into monosaccharides
- then converted into glucose or glycolytic intermediates
- glycogen in the liver can be converted into glucose 6-phosphate, a glycolytic intermediate

5 True/False questions

Cellular Metabolism → - the sum total of all chemical reactions that take place in a cell
- either anabolic (require energy) or catabolic (release energy)

True False

Proton Gradient → - the body degrades amino acids only when there isn't enough carbs available
- most amino acids undergo a transamination reaction where they lose an amino group to form an alpha-keto acid
- carbon atoms of most amino acids are converted into acetyl CoA, pyruvate or one of the intermediates of the citric acid cycle